Time for a Gravity Tractor?

Neil deGrasse Tyson wants a gravity tractor. Then if an asteroid comes careening on a collision course with Earth, we could tow it out of the way.

The possibility of a collision isn’t too far-fetched. Earth had a relatively near miss last month when Asteroid 2012 DA 14 came about 17,000 miles close to Earth. If it had hit, we would have had big trouble. Scientists think an asteroid collision wiped out the dinosaurs 65 million years ago.

NASA/JPL image by P. Chodas (NASA/JPL):

Why not blast an asteroid out of the sky like Bruce Willis did in the 1998 movie Armageddon?
Well, dealing with debris could be a big problem. “In America we’re really good at blowing stuff up, and we’re less good at knowing where the pieces fall,” Tyson told The Daily Show host Jon Stewart this week.

A gravity tractor isn’t far-fetched either. The solution would also involve a rocket launch. But instead of blasting an asteroid, the rocket would hover near it. The rocket and asteroid’s gravity would pull on each other. Things made of matter do that.

As that starts happening, jets on the rocket would move it slightly away from the asteroid. Gravity would get the asteroid to follow the rocket. Do this early enough, and you could change the asteroid’s path. Then it would miss the Earth.

Funding isn’t available yet for a gravity tractor. But maybe it’s something to consider. As Tyson said, “I don’t want to be the laughing stock of the galaxy when aliens learn that we all went extinct from an asteroid when we had a space program that could have done something about it. That would just be embarrassing.”